Spark-plug



c. B. WEST-COTT.

SPARK PLUG. I APPLICATION FILED AUG-27, 1918.

Patented Feb. 22, 1921 liliiwwv SEPARK PLUQ.

Specification of Letters Patent.

Patented Feb. 2, 31%21.

Application filed August 27, 1918. Serial No. 251,6. I

T all whom it may concern:

Be it known that l, Cnnanns B. Wss'rcour, a citizen of the United States, and a resident of Savannahfin the county of Chatham and State of Georgia, have invented a new and useful Improvement in Spark-Plugs, of which the following is a specification.

My invention relates to an improvement in spark plugs used in explosive engines,

and has for its objects toprovide means and mechanism by which the deposit of oil or carbon in the chamber of the plug is prevented, the porcelain or other insulation in the plug kept from overheating and short circuiting through or by reason of the electrodes coming in contact obviated.

Referring to my drawings in which. similar letters refer to similar parts in all views- Figure l is a vertical section of the threaded portion and part of the body of a well known type of spark plug. I do not deem it necessary to show in full detail the construction of the plug as it is well known to persons skilled in the art. Fig. 2is an elevation in perspective of a movable member or: sleeve. Fig. 3 is a. cross section of Fig. 1 about theline 1-42. A is the threaded portion and part of the body of a spark plug. ll is a crcelain insulator in the form of a tube. is a straight electrode. 1) is a sleeve which is provided with an axial bore D. The outline of D shown by broken electrodcs C and C 1.50

or dotted lines indicates the upward path of travel of D when in operation, but not necessarily its limit of travel. Its downward travel is limited by the electrode C". The sleeve, D, diametrically closes the chamber A, and it has a sliding fit, through the bore D, on the electrode C, and on the in terior wall of the chamber A. The periphery of D where it engages with wall of the chamber A is cylindrical, and below where it engages with the wall of the chamber D is preferably conical in contour. The diameter of D at its smaller end from its peripher'y to the bore 1) should be such that it will position when at rest between the and keep them separated to prevent short circuiting and yet not interfere with proper Sparking or ignition. While I prefer to use a slee e conical below its cylindrical portion, I do lot confine myself to that form. B should be non conducting, heat resisting material, prefcr- 5 ably porcelain or the like. i

In operation the compression stroke of the piston followed by the ex losion in the cylinder will force the sleeve upward into the chamber A until stopped by the tube, 6 B, or back pressure of gas or air above. D after the explosion and during the ezihaus and intake strokes of the piston will return to position between the electrodes.

The effect of the means and mechanism 6 shown in m drawings and hereinbefore described, is, 11st, to keep any excess (if oil that may be in the cylinder of the engine I from entering the chamber of the spark plug. Second, to protect the porcelain inl sulation, B, from the excessive heat generated in the cylinder of the engine by the explosions, thus removing one of the most common causes for the frequent breaking of the porcelain insulation in plugs. via, 7 sudden contraction or expansion oi the porcelain insulation. Third, to provide means to keep the electrodes of spark plugs from coming in contact.

Actual demonstration by months or cons 3 stant use has shown that spark plugs equipped with my invention-4t may be instantly applied to practically all of the plugs now in commercial use--cannot be will function perfectly under conditions in which ordinary plugs will work imperfectly or not at all. It has also been demonstrated by use that the porcelain insulation of plugs equipped with my invention remains com- 9 paratively cool under conditions where the insulation of similar plugs not so equipped becomes very hot.

It is my experience that the most freequent cause of imperfect ignition, or lack 9 of ignition, where the fault lies in the plug, is due to the flooding of the chamber of the spark plug with oil, the subsequent carbonization of the oil and sparking or short circuiting in the chamber of the plug. It is obvious that to close the chamber A by a non-movable member would not serve the purpose of my invention, as the surface of such non-movable member would be quickly covered. by a deposit of carbon, from im- 1 perfect combustion of gases and oil, and

- caries.

CHARLES B. WESTGOTT, 0F SAVANNAH, GEQRQIA;

short circuiting or imperfect sparking would result. The movement of the member D, keeps it free By the words from deposit. non-conducting matemal, 5 as used 111 this specification,

I mean a material that is a non-conductor of electricity.

1 claim: In a spark plug electrodes from com means for preventing the ing in contact at or near their firing point, such means consisting of 10 of non conducting, heat POSltlOIlGtl while at rest firing a movable member resisting material between the electrodes at or near their point. 1

' CHARLES B. \VESTCOTT.

Witnesses CHARLOTTE B, lownns,

RICHARD M. Lns'rmx. 

